• java写bfs


    Find a way

     HDU - 2612

    Pass a year learning in Hangzhou, yifenfei arrival hometown Ningbo at finally. Leave Ningbo one year, yifenfei have many people to meet. Especially a good friend Merceki. 
    Yifenfei’s home is at the countryside, but Merceki’s home is in the center of city. So yifenfei made arrangements with Merceki to meet at a KFC. There are many KFC in Ningbo, they want to choose one that let the total time to it be most smallest. 
    Now give you a Ningbo map, Both yifenfei and Merceki can move up, down ,left, right to the adjacent road by cost 11 minutes. 

    InputThe input contains multiple test cases. 
    Each test case include, first two integers n, m. (2<=n,m<=200). 
    Next n lines, each line included m character. 
    ‘Y’ express yifenfei initial position. 
    ‘M’    express Merceki initial position. 
    ‘#’ forbid road; 
    ‘.’ Road. 
    ‘@’ KCF 
    OutputFor each test case output the minimum total time that both yifenfei and Merceki to arrival one of KFC.You may sure there is always have a KFC that can let them meet.Sample Input

    4 4
    Y.#@
    ....
    .#..
    @..M
    4 4
    Y.#@
    ....
    .#..
    @#.M
    5 5
    Y..@.
    .#...
    .#...
    @..M.
    #...#

    Sample Output

    66
    88
    66
      1 import java.util.ArrayDeque;
      2 import java.util.PriorityQueue;
      3 import java.util.Scanner;
      4 class node{
      5     int x;
      6     int y;
      7     int step;
      8     int flag;
      9 }
     10 public class Main {
     11     static int n,m;
     12     static int [][][] vis = new int[220][220][2];
     13     static char[][] c = new char[220][220];
     14     static int [][][] dis = new int[220][220][2];
     15     static String[] s = new String[220];
     16     static int [][] dir = {{1,0},{0,1},{-1,0},{0,-1}};
     17     static node head,tail;
     18     static ArrayDeque<node> q = new ArrayDeque<node>();
     19     static void bfs() {
     20         while(!q.isEmpty()) {
     21             head = q.poll();
     22             //System.out.println(head.x+" "+head.y+" "+head.flag);
     23             //System.out.println("lallaa"+vis[head.x][head.y][head.flag]);
     24             for(int i=0;i<4;i++) {
     25                 int tx = head.x+dir[i][0];
     26                 int ty = head.y+dir[i][1];
     27                 int tstep = head.step + 1;
     28                 if(tx<0||tx>=n||ty<0||ty>=m||c[tx][ty]=='#'||vis[tx][ty][head.flag]==1)
     29                     continue;
     30                 if(c[tx][ty]=='@') {
     31                     if(head.flag==0) {
     32                     //    System.out.println("haah");
     33                         dis[tx][ty][0] = Math.min(dis[tx][ty][0], tstep);
     34                         vis[tx][ty][0] = 1;
     35                     }
     36                     else if(head.flag==1) {
     37                         dis[tx][ty][1] = Math.min(dis[tx][ty][1], tstep);
     38                         vis[tx][ty][1] = 1;
     39                     }
     40                 }
     41                 vis[tx][ty][head.flag] = 1;
     42                 tail = new node();
     43                 tail.flag = head.flag;
     44                 tail.step = head.step + 1;
     45                 tail.x = tx;
     46                 tail.y = ty;
     47                 q.offer(tail);
     48             }
     49         }
     50     }
     51     public static void main(String[] args) {
     52         Scanner cin = new Scanner(System.in);
     53         while(cin.hasNext()) {
     54             n = cin.nextInt();
     55             m = cin.nextInt();
     56             for(int i=0;i<n;i++) {
     57                 for(int j=0;j<m;j++) {
     58                     for(int k=0;k<2;k++) {
     59                         dis[i][j][k] = 1000000;
     60                     }
     61                 }
     62             }
     63             for(int i=0;i<n;i++) {
     64                 for(int j=0;j<m;j++) {
     65                     for(int k=0;k<2;k++) {
     66                         vis[i][j][k] = 0;
     67                     }
     68                 }
     69             }
     70             for(int i=0;i<n;i++) {
     71                 s[i] = cin.next();
     72             }
     73             for(int i=0;i<n;i++) {
     74                 for(int j=0;j<s[i].length();j++) {
     75                     c[i][j] = s[i].charAt(j);
     76                     if(c[i][j] == 'Y') {
     77                         head = new node();
     78                         head.step = 0;
     79                         head.flag = 0;
     80                         head.x = i;
     81                         head.y = j;
     82                         q.offer(head);
     83                         vis[i][j][0] = 1;
     84                         //bfs();
     85                     }
     86                     if(c[i][j] == 'M') {
     87                         head = new node();
     88                         head.step = 0;
     89                         head.flag = 1;
     90                         head.x = i;
     91                         head.y = j;
     92                         q.offer(head);
     93                         vis[i][j][1] = 1;
     94                         
     95                     }
     96                 }
     97             }
     98             bfs();
     99             int ans = 1000000;
    100             for(int i=0;i<n;i++) {
    101                 for(int j=0;j<m;j++) {
    102                     if(c[i][j] == '@') {
    103                         ans = Math.min(ans,dis[i][j][0]+dis[i][j][1]);
    104                     }
    105                 }
    106             }
    107             System.out.println(ans*11);
    108         }
    109     }
    110 }
  • 相关阅读:
    java:transient是什么,有什么作用
    如何阅读java源码
    java里面list是引用的好例子
    sort给文件按照大小排序
    HBase的rowkey排序和scan输出顺序
    记录一次事故——idea,sbt,scala
    一个简单的synchronized多线程问题、梳理与思考
    Android TextView文字描边的实现!!
    android中include标签的使用
    layout_weight 的解释及使用
  • 原文地址:https://www.cnblogs.com/1013star/p/10353589.html
Copyright © 2020-2023  润新知